Commit Graph

110 Commits

Author SHA1 Message Date
Christoph Hellwig
efc3c1df5f scsi: remove ->change_queue_type method
Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete.  The other function
of enabling/disabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-12-04 09:55:45 +01:00
Christoph Hellwig
db5ed4dfd5 scsi: drop reason argument from ->change_queue_depth
Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24 14:45:27 +01:00
Christoph Hellwig
1e6f241604 scsi: don't allow setting of queue_depth bigger than can_queue
We won't ever queue more commands than the host allows.  Instead of
letting drivers either reject or ignore this case handle it in
common code.  Note that various driver use internal constant or
variables that are assigned to both shost->can_queue and checked
in ->change_queue_depth - I did remove those checks as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24 14:45:26 +01:00
Christoph Hellwig
609aa22f3b scsi: remove ordered_tags scsi_device field
Remove the ordered_tags field, we haven't been issuing ordered tags based
on it since the big barrier rework in 2010.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12 11:19:40 +01:00
Subhash Jadavani
6fe8c1dbef scsi: balance out autopm get/put calls in scsi_sysfs_add_sdev()
SCSI Well-known logical units generally don't have any scsi driver
associated with it which means no one will call scsi_autopm_put_device()
on these wlun scsi devices and this would result in keeping the
corresponding scsi device always active (hence LLD can't be suspended as
well). Same exact problem can be seen for other scsi device representing
normal logical unit whose driver is yet to be loaded. This patch fixes
the above problem with this approach:

- make the scsi_autopm_put_device call at the end of scsi_sysfs_add_sdev
  to make it balance out the get earlier in the function.
- let drivers do paired get/put calls in their probe methods.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-09-15 16:02:05 -07:00
Alan Stern
50c4e96411 scsi: don't store LUN bits in CDB[1] for USB mass-storage devices
The SCSI specification requires that the second Command Data Byte
should contain the LUN value in its high-order bits if the recipient
device reports SCSI level 2 or below.  Nevertheless, some USB
mass-storage devices use those bits for other purposes in
vendor-specific commands.  Currently Linux has no way to send such
commands, because the SCSI stack always overwrites the LUN bits.

Testing shows that Windows 7 and XP do not store the LUN bits in the
CDB when sending commands to a USB device.  This doesn't matter if the
device uses the Bulk-Only or UAS transports (which virtually all
modern USB mass-storage devices do), as these have a separate
mechanism for sending the LUN value.

Therefore this patch introduces a flag in the Scsi_Host structure to
inform the SCSI midlayer that a transport does not require the LUN
bits to be stored in the CDB, and it makes usb-storage set this flag
for all devices using the Bulk-Only transport.  (UAS is handled by a
separate driver, but it doesn't really matter because no SCSI-2 or
lower device is at all likely to use UAS.)

The patch also cleans up the code responsible for storing the LUN
value by adding a bitflag to the scsi_device structure.  The test for
whether to stick the LUN value in the CDB can be made when the device
is probed, and stored for future use rather than being made over and
over in the fast path.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Tiziano Bacocco <tiziano.bacocco@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-09-15 16:01:58 -07:00
Daniel Walter
f7c65af513 drivers/scsi: replace strict_strto calls
Replace obsolete strict_strto with more appropriate kstrto calls

Signed-off-by: Daniel Walter <dwalter@google.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:28 -07:00
Christoph Hellwig
d285203cf6 scsi: add support for a blk-mq based I/O path.
This patch adds support for an alternate I/O path in the scsi midlayer
which uses the blk-mq infrastructure instead of the legacy request code.

Use of blk-mq is fully transparent to drivers, although for now a host
template field is provided to opt out of blk-mq usage in case any unforseen
incompatibilities arise.

In general replacing the legacy request code with blk-mq is a simple and
mostly mechanical transformation.  The biggest exception is the new code
that deals with the fact the I/O submissions in blk-mq must happen from
process context, which slightly complicates the I/O completion handler.
The second biggest differences is that blk-mq is build around the concept
of preallocated requests that also include driver specific data, which
in SCSI context means the scsi_cmnd structure.  This completely avoids
dynamic memory allocations for the fast path through I/O submission.

Due the preallocated requests the MQ code path exclusively uses the
host-wide shared tag allocator instead of a per-LUN one.  This only
affects drivers actually using the block layer provided tag allocator
instead of their own.  Unlike the old path blk-mq always provides a tag,
although drivers don't have to use it.

For now the blk-mq path is disable by defauly and must be enabled using
the "use_blk_mq" module parameter.  Once the remaining work in the block
layer to make blk-mq more suitable for slow devices is complete I hope
to make it the default and eventually even remove the old code path.

Based on the earlier scsi-mq prototype by Nicholas Bellinger.

Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and
various sugestions and code contributions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25 17:16:28 -04:00
Christoph Hellwig
cd9070c9c5 scsi: fix the {host,target,device}_blocked counter mess
Seems like these counters are missing any sort of synchronization for
updates, as a over 10 year old comment from me noted.  Fix this by
using atomic counters, and while we're at it also make sure they are
in the same cacheline as the _busy counters and not needlessly stored
to in every I/O completion.

With the new model the _busy counters can temporarily go negative,
so all the readers are updated to check for > 0 values.  Longer
term every successful I/O completion will reset the counters to zero,
so the temporarily negative values will not cause any harm.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25 17:15:48 -04:00
Christoph Hellwig
71e75c97f9 scsi: convert device_busy to atomic_t
Avoid taking the queue_lock to check the per-device queue limit.  Instead
we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Unlike the host and target busy counters this doesn't allow us to avoid the
queue_lock in the request_fn due to the way the interface works, but it'll
allow us to prepare for using the blk-mq code, which doesn't use the
queue_lock at all, and it at least avoids a queue_lock round trip in
scsi_device_unbusy, which is still important given how busy the queue_lock
is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25 07:43:45 -04:00
Christoph Hellwig
7466501608 scsi: convert host_busy to atomic_t
Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25 07:43:43 -04:00
Hannes Reinecke
9cb78c16f5 scsi: use 64-bit LUNs
The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-17 22:07:37 +02:00
Linus Torvalds
1a0b6abaea SCSI misc on 20140401
This patch consists of the usual driver updates (megaraid_sas, scsi_debug,
 qla2xxx, qla4xxx, lpfc, bnx2fc, be2iscsi, hpsa, ipr) plus an assortment of
 minor fixes and the first precursors of SCSI-MQ (the code path
 simplifications) and the bug fix for the USB oops on remove (which involves an
 infrastructure change, so is sent via the main tree with a delayed backport
 after a cycle in which it is shown to introduce no new bugs).
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull first round of SCSI updates from James Bottomley:
 "This patch consists of the usual driver updates (megaraid_sas,
  scsi_debug, qla2xxx, qla4xxx, lpfc, bnx2fc, be2iscsi, hpsa, ipr) plus
  an assortment of minor fixes and the first precursors of SCSI-MQ (the
  code path simplifications) and the bug fix for the USB oops on remove
  (which involves an infrastructure change, so is sent via the main tree
  with a delayed backport after a cycle in which it is shown to
  introduce no new bugs)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (196 commits)
  [SCSI] sd: Quiesce mode sense error messages
  [SCSI] add support for per-host cmd pools
  [SCSI] simplify command allocation and freeing a bit
  [SCSI] megaraid: simplify internal command handling
  [SCSI] ses: Use vpd information from scsi_device
  [SCSI] Add EVPD page 0x83 and 0x80 to sysfs
  [SCSI] Return VPD page length in scsi_vpd_inquiry()
  [SCSI] scsi_sysfs: Implement 'is_visible' callback
  [SCSI] hpsa: update driver version to 3.4.4-1
  [SCSI] hpsa: fix bad endif placement in RAID 5 mapper code
  [SCSI] qla2xxx: Fix build errors related to invalid print fields on some architectures.
  [SCSI] bfa: Replace large udelay() with mdelay()
  [SCSI] vmw_pvscsi: Some improvements in pvscsi driver.
  [SCSI] vmw_pvscsi: Add support for I/O requests coalescing.
  [SCSI] vmw_pvscsi: Fix pvscsi_abort() function.
  [SCSI] remove deprecated IRQF_DISABLED from SCSI
  [SCSI] bfa: Updating Maintainers email ids
  [SCSI] ipr: Add new CCIN definition for Grand Canyon support
  [SCSI] ipr: Format HCAM overlay ID 0x21
  [SCSI] ipr: Use pci_enable_msi_range() and pci_enable_msix_range()
  ...
2014-04-01 18:49:04 -07:00
Hannes Reinecke
b3ae8780b4 [SCSI] Add EVPD page 0x83 and 0x80 to sysfs
EVPD page 0x83 is used to uniquely identify the device.
So instead of having each and every program issue a separate
SG_IO call to retrieve this information it does make far more
sense to display it in sysfs.

Some older devices (most notably tapes) will only report reliable
information in page 0x80 (Unit Serial Number). So export this
in the sysfs attribute 'vpd_pg80'.

[jejb: checkpatch fix]
[hare: attach after transport configure]
[fengguang.wu@intel.com: spotted problems with the original now fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27 08:25:33 -07:00
Hannes Reinecke
276b20d09b [SCSI] scsi_sysfs: Implement 'is_visible' callback
Instead of modifying attributes after the device has been created
we should be using the 'is_visible' callback to avoid races.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-19 15:22:39 -07:00
Hannes Reinecke
ad469a5764 [SCSI] scsi_error: disable eh_deadline if no host_reset_handler is set
When the host template doesn't declare an eh_host_reset_handler
the eh_deadline mechanism is pointless and will set the
device to offline. So disable eh_deadline if no
eh_host_reset_handler is present.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:18:59 -07:00
James Bottomley
e63ed0d7a9 [SCSI] fix our current target reap infrastructure
This patch eliminates the reap_ref and replaces it with a proper kref.
On last put of this kref, the target is removed from visibility in
sysfs.  The final call to scsi_target_reap() for the device is done from
__scsi_remove_device() and only if the device was made visible.  This
ensures that the target disappears as soon as the last device is gone
rather than waiting until final release of the device (which is often
too long).

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # delay backport by 2 months for field testing
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:18:59 -07:00
Tejun Heo
ac0ece9174 scsi: use device_remove_file_self() instead of device_schedule_callback()
driver-core now supports synchrnous self-deletion of attributes and
the asynchrnous removal mechanism is scheduled for removal.  Use it
instead of device_schedule_callback().  This makes "delete" behave
synchronously.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 15:42:41 -08:00
Ren Mingxin
bb3b621a33 [SCSI] Set the minimum valid value of 'eh_deadline' as 0
The former minimum valid value of 'eh_deadline' is 1s, which means
the earliest occasion to shorten EH is 1 second later since a
command is failed or timed out. But if we want to skip EH steps
ASAP, we have to wait until the first EH step is finished. If the
duration of the first EH step is long, this waiting time is
excruciating. So, it is necessary to accept 0 as the minimum valid
value for 'eh_deadline'.

According to my test, with Hannes' patchset 'New EH command timeout
handler' as well, the minimum IO time is improved from 73s
(eh_deadline = 1) to 43s(eh_deadline = 0) when commands are timed
out by disabling RSCN and target port.

Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:39:02 -08:00
Hannes Reinecke
b45620229d [SCSI] Add 'eh_deadline' to limit SCSI EH runtime
This patchs adds an 'eh_deadline' sysfs attribute to the scsi
host which limits the overall runtime of the SCSI EH.
The 'eh_deadline' value is stored in the now obsolete field
'resetting'.
When a command is failed the start time of the EH is stored
in 'last_reset'. If the overall runtime of the SCSI EH is longer
than last_reset + eh_deadline, the EH is short-circuited and
falls through to issue a host reset only.

[jejb: add comments in Scsi_Host about new fields]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-10-25 12:17:59 +01:00
Jack Wang
522db3c9e1 [SCSI] export device_busy for sdev
If you mutiple devices connect to a host, we might be interested in
have an intensive I/O workload on one disk, and notice starvation on others.
This give the user more hint about current infight io for scsi device.

Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-10-25 09:57:56 +01:00
Ewan D. Milne
279afdfe78 [SCSI] Generate uevents on certain unit attention codes
Generate a uevent when the following Unit Attention ASC/ASCQ
codes are received:

    2A/01  MODE PARAMETERS CHANGED
    2A/09  CAPACITY DATA HAS CHANGED
    38/07  THIN PROVISIONING SOFT THRESHOLD REACHED
    3F/03  INQUIRY DATA HAS CHANGED
    3F/0E  REPORTED LUNS DATA HAS CHANGED

Log kernel messages when the following Unit Attention ASC/ASCQ
codes are received that are not as specific as those above:

    2A/xx  PARAMETERS CHANGED
    3F/xx  TARGET OPERATING CONDITIONS HAVE CHANGED

Added logic to set expecting_lun_change for other LUNs on the target
after REPORTED LUNS DATA HAS CHANGED is received, so that duplicate
uevents are not generated, and clear expecting_lun_change when a
REPORT LUNS command completes, in accordance with the SPC-3
specification regarding reporting of the 3F 0E ASC/ASCQ UA.

[jejb: remove SPC3 test in scsi_report_lun_change and some docbook fixes and
       unused variable fix, both reported by Fengguang Wu]
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-26 18:52:27 +04:00
Martin K. Petersen
0816c9251a [SCSI] Allow error handling timeout to be specified
Introduce eh_timeout which can be used for error handling purposes. This
was previously hardcoded to 10 seconds in the SCSI error handling
code. However, for some fast-fail scenarios it is necessary to be able
to tune this as it can take several iterations (bus device, target, bus,
controller) before we give up.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-06-04 11:16:24 -07:00
Sasha Levin
072f19b4be [SCSI] prevent stack buffer overflow in host_reset
store_host_reset() has tried to re-invent the wheel to compare sysfs strings.
Unfortunately it did so poorly and never bothered to check the input from
userspace before overwriting stack with it, so something simple as:

echo "WoopsieWoopsie" >
/sys/devices/pseudo_0/adapter0/host0/scsi_host/host0/host_reset

would result in:

[  316.310101] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81f5bac7
[  316.310101]
[  316.320051] Pid: 6655, comm: sh Tainted: G        W    3.7.0-rc5-next-20121114-sasha-00016-g5c9d68d-dirty #129
[  316.320051] Call Trace:
[  316.340058] pps pps0: PPS event at 1352918752.620355751
[  316.340062] pps pps0: capture assert seq #303
[  316.320051]  [<ffffffff83b3856b>] panic+0xcd/0x1f4
[  316.320051]  [<ffffffff81f5bac7>] ? store_host_reset+0xd7/0x100
[  316.320051]  [<ffffffff8110b996>] __stack_chk_fail+0x16/0x20
[  316.320051]  [<ffffffff81f5bac7>] store_host_reset+0xd7/0x100
[  316.320051]  [<ffffffff81e55bb3>] dev_attr_store+0x13/0x30
[  316.320051]  [<ffffffff812f7db1>] sysfs_write_file+0x101/0x170
[  316.320051]  [<ffffffff8127acc8>] vfs_write+0xb8/0x180
[  316.320051]  [<ffffffff8127ae80>] sys_write+0x50/0xa0
[  316.320051]  [<ffffffff83c03418>] tracesys+0xe1/0xe6

Fix this by uninventing whatever was going on there and just use sysfs_streq.

Bug introduced by 29443691 ("[SCSI] scsi: Added support for adapter and
firmware reset").

[jejb: added necessary const to prevent compile warnings]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: <stable@vger.kernel.org> #3.2+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-11-30 09:08:16 +00:00
Dan Williams
bc3f02a795 [SCSI] scsi_remove_target: fix softlockup regression on hot remove
John reports:
 BUG: soft lockup - CPU#2 stuck for 23s! [kworker/u:8:2202]
 [..]
 Call Trace:
  [<ffffffff8141782a>] scsi_remove_target+0xda/0x1f0
  [<ffffffff81421de5>] sas_rphy_remove+0x55/0x60
  [<ffffffff81421e01>] sas_rphy_delete+0x11/0x20
  [<ffffffff81421e35>] sas_port_delete+0x25/0x160
  [<ffffffff814549a3>] mptsas_del_end_device+0x183/0x270

...introduced by commit 3b661a9 "[SCSI] fix hot unplug vs async scan race".

Don't restart lookup of more stargets in the multi-target case, just
arrange to traverse the list once, on the assumption that new targets
are always added at the end.  There is no guarantee that the target will
change state in scsi_target_reap() so we can end up spinning if we
restart.

Cc: <stable@vger.kernel.org>
Acked-by: Jack Wang <jack_wang@usish.com>
LKML-Reference: <CAEhu1-6wq1YsNiscGMwP4ud0Q+MrViRzv=kcWCQSBNc8c68N5Q@mail.gmail.com>
Reported-by: John Drescher <drescherjm@gmail.com>
Tested-by: John Drescher <drescherjm@gmail.com>
Signed-off-by: Dan Williams <djbw@fb.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-09-24 12:17:49 +04:00
Dan Williams
3b661a92e8 [SCSI] fix hot unplug vs async scan race
The following crash results from cases where the end_device has been
removed before scsi_sysfs_add_sdev has had a chance to run.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
 IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6
 ...
 Call Trace:
  [<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3
  [<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf
  [<ffffffff8125e641>] kobject_add_varg+0x41/0x50
  [<ffffffff8125e70b>] kobject_add+0x64/0x66
  [<ffffffff8131122b>] device_add+0x12d/0x63a
  [<ffffffff814b65ea>] ? _raw_spin_unlock_irqrestore+0x47/0x56
  [<ffffffff8107de15>] ? module_refcount+0x89/0xa0
  [<ffffffff8132f348>] scsi_sysfs_add_sdev+0x4e/0x28a
  [<ffffffff8132dcbb>] do_scan_async+0x9c/0x145

...teach scsi_sysfs_add_devices() to check for deleted devices() before
trying to add them, and teach scsi_remove_target() how to remove targets
that have not been added via device_add().

Cc: <stable@vger.kernel.org>
Reported-by: Dariusz Majchrzak <dariusz.majchrzak@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20 08:58:45 +01:00
Bart Van Assche
b485462aca [SCSI] Stop accepting SCSI requests before removing a device
Avoid that the code for requeueing SCSI requests triggers a
crash by making sure that that code isn't scheduled anymore
after a device has been removed.

Also, source code inspection of __scsi_remove_device() revealed
a race condition in this function: no new SCSI requests must be
accepted for a SCSI device after device removal started.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20 08:58:41 +01:00
Bart Van Assche
67bd941300 [SCSI] Fix device removal NULL pointer dereference
Use blk_queue_dead() to test whether the queue is dead instead
of !sdev. Since scsi_prep_fn() may be invoked concurrently with
__scsi_remove_device(), keep the queuedata (sdev) pointer in
__scsi_remove_device(). This patch fixes a kernel oops that
can be triggered by USB device removal. See also
http://www.spinics.net/lists/linux-scsi/msg56254.html.

Other changes included in this patch:
- Swap the blk_cleanup_queue() and kfree() calls in
  scsi_host_dev_release() to make that code easier to grasp.
- Remove the queue dead check from scsi_run_queue() since the
  queue state can change anyway at any point in that function
  where the queue lock is not held.
- Remove the queue dead check from the start of scsi_request_fn()
  since it is redundant with the scsi_device_online() check.

Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20 08:58:40 +01:00
Mike Christie
1b8d262061 [SCSI] add new SDEV_TRANSPORT_OFFLINE state
This patch adds a new state SDEV_TRANSPORT_OFFLINE. It will
be used by transport classes to offline devices for cases like
when the fast_io_fail/recovery_tmo fires. In those cases we
want all IO to fail, and we have not yet escalated to dev_loss_tmo
behavior where we are removing the devices.

Currently to handle this state, transport classes are setting
the scsi_device's state to running, setting their internal
session/port structs state to something that indicates failed,
and then failing IO from some transport check in the queuecommand.

The reason for the new value is so that users can distinguish
between a device failure that is a result of a transport problem
vs the wide range of errors that devices get offlined for
when a scsi command times out and we offline the devices there.
It also fixes the confusion as to why the transport class is
failing IO, but has set the device state from blocked to running.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20 08:58:21 +01:00
Vikas Chaudhary
2944369144 [SCSI] scsi: Added support for adapter and firmware reset
Added new sysfs attr 'host_reset' in scsi_sysfs.c to
perform adapter or firmware reset as suggested by
Mike Christie here:
http://marc.info/?l=linux-scsi&m=127359347111167&w=2

user/application can write "adapter" or "firmware" on
this attr and it will call newly added function hook
in scsi_host_template to call LDD adapter or firmware
reset implementation.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-08-27 08:36:46 -06:00
James Bottomley
e73e079bf1 [SCSI] Fix oops caused by queue refcounting failure
In certain circumstances, we can get an oops from a torn down device.
Most notably this is from CD roms trying to call scsi_ioctl.  The root
cause of the problem is the fact that after scsi_remove_device() has
been called, the queue is fully torn down.  This is actually wrong
since the queue can be used until the sdev release function is called.
Therefore, we add an extra reference to the queue which is released in
sdev->release, so the queue always exists.

Reported-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>
2011-06-02 18:34:43 +09:00
James Bottomley
86cbfb5607 [SCSI] put stricter guards on queue dead checks
SCSI uses request_queue->queuedata == NULL as a signal that the queue
is dying.  We set this state in the sdev release function.  However,
this allows a small window where we release the last reference but
haven't quite got to this stage yet and so something will try to take
a reference in scsi_request_fn and oops.  It's very rare, but we had a
report here, so we're pushing this as a bug fix

The actual fix is to set request_queue->queuedata to NULL in
scsi_remove_device() before we drop the reference.  This causes
correct automatic rejects from scsi_request_fn as people who hold
additional references try to submit work and prevents anything from
getting a new reference to the sdev that way.

Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-04-24 11:02:17 -05:00
Rafael J. Wysocki
aa33860158 PM: Remove CONFIG_PM_OPS
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Linus Torvalds
008d23e485 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  Documentation/trace/events.txt: Remove obsolete sched_signal_send.
  writeback: fix global_dirty_limits comment runtime -> real-time
  ppc: fix comment typo singal -> signal
  drivers: fix comment typo diable -> disable.
  m68k: fix comment typo diable -> disable.
  wireless: comment typo fix diable -> disable.
  media: comment typo fix diable -> disable.
  remove doc for obsolete dynamic-printk kernel-parameter
  remove extraneous 'is' from Documentation/iostats.txt
  Fix spelling milisec -> ms in snd_ps3 module parameter description
  Fix spelling mistakes in comments
  Revert conflicting V4L changes
  i7core_edac: fix typos in comments
  mm/rmap.c: fix comment
  sound, ca0106: Fix assignment to 'channel'.
  hrtimer: fix a typo in comment
  init/Kconfig: fix typo
  anon_inodes: fix wrong function name in comment
  fix comment typos concerning "consistent"
  poll: fix a typo in comment
  ...

Fix up trivial conflicts in:
 - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
 - fs/ext4/ext4.h

Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-13 10:05:56 -08:00
Alan Stern
41511704b6 [SCSI] eliminate an unnecessary local variable from scsi_remove_target()
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-01-03 10:30:27 -06:00
Jiri Kosina
4b7bd36470 Merge branch 'master' into for-next
Conflicts:
	MAINTAINERS
	arch/arm/mach-omap2/pm24xx.c
	drivers/scsi/bfa/bfa_fcpim.c

Needed to update to apply fixes for which the old branch was too
outdated.
2010-12-22 18:57:02 +01:00
Alan Stern
73d8c34f3d SCSI: improve two error messages
This trivial patch (as1338) makes two uninformative error messages in
scsi_sysfs_add_sdev() more explicit.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-26 15:43:34 +01:00
Christof Schmitt
546ae796bf [SCSI] Fix race when removing SCSI devices
Removing SCSI devices through
echo 1 > /sys/bus/scsi/devices/ ... /delete

while the FC transport class removes the SCSI target can lead to an
oops:

Unable to handle kernel pointer dereference at virtual kernel address 00000000b6815000
Oops: 0011 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: sunrpc qeth_l3 binfmt_misc dm_multipath scsi_dh dm_mod ipv6 qeth ccwgroup [last unloaded: scsi_wait_scan]
CPU: 1 Not tainted 2.6.35.5-45.x.20100924-s390xdefault #1
Process fc_wq_0 (pid: 861, task: 00000000b7331240, ksp: 00000000b735bac0)
Krnl PSW : 0704200180000000 00000000003ff6e4 (__scsi_remove_device+0x24/0xd0)
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3
Krnl GPRS: 0000000000000001 0000000000000000 00000000b6815000 00000000bc24a8c0
           00000000003ff7c8 000000000056dbb8 0000000000000002 0000000000835d80
           ffffffff00000000 0000000000001000 00000000b6815000 00000000bc24a7f0
           00000000b68151a0 00000000b6815000 00000000b735bc20 00000000b735bbf8
Krnl Code: 00000000003ff6d6: a7840001            brc 8,3ff6d8
           00000000003ff6da: a7fbffd8            aghi %r15,-40
           00000000003ff6de: e3e0f0980024        stg %r14,152(%r15)
          >00000000003ff6e4: e31021200004        lg %r1,288(%r2)
           00000000003ff6ea: a71f0000            cghi    %r1,0
           00000000003ff6ee: a7a40011            brc 10,3ff710
           00000000003ff6f2: a7390003            lghi    %r3,3
           00000000003ff6f6: c0e5ffffc8b1        brasl %r14,3f8858
Call Trace:
([<0000000000001000>] 0x1000)
 [<00000000003ff7d2>] scsi_remove_device+0x42/0x54
 [<00000000003ff8ba>] __scsi_remove_target+0xca/0xfc
 [<00000000003ff99a>] __remove_child+0x3a/0x48
 [<00000000003e3246>] device_for_each_child+0x72/0xbc
 [<00000000003ff93a>] scsi_remove_target+0x4e/0x74
 [<0000000000406586>] fc_rport_final_delete+0xb2/0x23c
 [<000000000015d080>] worker_thread+0x200/0x344
 [<000000000016330c>] kthread+0xa0/0xa8
 [<0000000000106c1a>] kernel_thread_starter+0x6/0xc
 [<0000000000106c14>] kernel_thread_starter+0x0/0xc
INFO: lockdep is turned off.
Last Breaking-Event-Address:
 [<00000000003ff7cc>] scsi_remove_device+0x3c/0x54

The function __scsi_remove_target iterates through the SCSI devices on
the host, but it drops the host_lock before calling
scsi_remove_device. When the SCSI device is deleted from another
thread, the pointer to the SCSI device in scsi_remove_device can
become invalid. Fix this by getting a reference to the SCSI device
before dropping the host_lock to keep the SCSI device alive for the
call to scsi_remove_device.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-10-25 15:00:47 -05:00
Martin K. Petersen
13f05c8d8e block/scsi: Provide a limit on the number of integrity segments
Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.

Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.

Add support for honoring the integrity segment limit when merging both
bios and requests.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2010-09-10 20:50:10 +02:00
Alan Stern
e6da54d84f SCSI: remove fake "address-of" expression
Fake "address-of" expressions that evaluate to NULL generally confuse
readers and can provoke compiler warnings.  This patch (as1411) removes
one such fake expression, using an "#ifdef" in its place.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-06 09:17:02 -07:00
Alan Stern
bc4f24014d [SCSI] implement runtime Power Management
This patch (as1398b) adds runtime PM support to the SCSI layer.  Only
the machanism is provided; use of it is up to the various high-level
drivers, and the patch doesn't change any of them.  Except for sg --
the patch expicitly prevents a device from being runtime-suspended
while its sg device file is open.

The implementation is simplistic.  In general, hosts and targets are
automatically suspended when all their children are asleep, but for
them the runtime-suspend code doesn't actually do anything.  (A host's
runtime PM status is propagated up the device tree, though, so a
runtime-PM-aware lower-level driver could power down the host adapter
hardware at the appropriate times.)  There are comments indicating
where a transport class might be notified or some other hooks added.

LUNs are runtime-suspended by calling the drivers' existing suspend
handlers (and likewise for runtime-resume).  Somewhat arbitrarily, the
implementation delays for 100 ms before suspending an eligible LUN.
This is because there typically are occasions during bootup when the
same device file is opened and closed several times in quick
succession.

The way this all works is that the SCSI core increments a device's
PM-usage count when it is registered.  If a high-level driver does
nothing then the device will not be eligible for runtime-suspend
because of the elevated usage count.  If a high-level driver wants to
use runtime PM then it can call scsi_autopm_put_device() in its probe
routine to decrement the usage count and scsi_autopm_get_device() in
its remove routine to restore the original count.

Hosts, targets, and LUNs are not suspended while they are being probed
or removed, or while the error handler is running.  In fact, a fairly
large part of the patch consists of code to make sure that things
aren't suspended at such times.

[jejb: fix up compile issues in PM config variations]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:07:50 -05:00
Alan Stern
db5bd1e0b5 [SCSI] convert to the new PM framework
This patch (as1397b) converts the SCSI midlayer to use the new PM
callbacks (struct dev_pm_ops).  A new source file, scsi_pm.c, is
created to hold the new callback routines, and the existing
suspend/resume code is moved there.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:07:49 -05:00
Tomohiro Kusumi
160e7f6713 [SCSI] fix sdev_rw_attr macro for scsi device sysfs entries
This patch fixes sdev_rw_attr() macro for scsi device sysfs entries.
It seems there is no such function snscanf in the current linux kernel,
so it fails to compile scsi driver when someone try to add a new rw entry.
This has been unfixed for a long time probably because current scsi device
has no rw entries.

# grep snscanf . -rn
./drivers/scsi/scsi_sysfs.c:489:        snscanf (buf, 20, format_string, &sdev->field);                 \

Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-05-01 14:16:30 -05:00
Alan Stern
1821438a9b [SCSI] don't reap targets upon device_add failure
This patch (as1358) fixes a bug in the error pathway of
scsi_target_add().  If registration fails, the target should not be
reaped.  The reaping occurs later, when scanning is finished and all
the child devices are removed.  The current code leaves an unbalanced
value in starget->reap_ref.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-04-11 09:24:15 -05:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Linus Torvalds
06a79b82b2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / Hibernate: Fix preallocating of memory
  PM / Hibernate: Remove swsusp.c finally
  PM / Hibernate: Remove trailing space in message
  PM: Allow SCSI devices to suspend/resume asynchronously
  PM: Allow USB devices to suspend/resume asynchronously
  USB: implement non-tree resume ordering constraints for PCI host controllers
  PM: Allow PCI devices to suspend/resume asynchronously
  PM / Hibernate: Swap, remove useless check from swsusp_read()
  PM / Hibernate: Really deprecate deprecated user ioctls
  PM: Allow device drivers to use dpm_wait()
  PM: Start asynchronous resume threads upfront
  PM: Add facility for advanced testing of async suspend/resume
  PM: Add a switch for disabling/enabling asynchronous suspend/resume
  PM: Asynchronous suspend and resume of devices
  PM: Add parent information to timing messages
  PM: Document device power attributes in sysfs
  PM / Runtime: Add sysfs switch for disabling device run-time PM
2010-02-26 17:22:53 -08:00
Rafael J. Wysocki
4cb077d93a PM: Allow SCSI devices to suspend/resume asynchronously
Set power.async_suspend for all SCSI devices, targets and hosts, so
that they can be suspended and resumed in parallel with the main
suspend/resume thread and possibly with other devices they don't
depend on in a known way (i.e. devices which are not their parents or
children).

The power.async_suspend flag is also set for devices that don't have
suspend or resume callbacks, because otherwise they would make the
main suspend/resume thread wait for their "asynchronous" children
(during suspend) or parents (during resume), effectively negating the
possible gains from executing these devices' suspend and resume
callbacks asynchronously.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26 20:39:12 +01:00
Alan Stern
ee37e09d81 [SCSI] fix duplicate removal on error path in scsi_sysfs_add_sdev
This patch (as1335) fixes a bug in scsi_sysfs_add_sdev().  Its callers
always remove the device if anything goes wrong, so it should never
remove the device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-02-18 11:06:39 -06:00
Linus Torvalds
382f51fe2f Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits)
  [SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP
  [SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class
  [SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED
  [SCSI] zfcp: Update FSF error reporting
  [SCSI] zfcp: Improve ELS ADISC handling
  [SCSI] zfcp: Simplify handling of ct and els requests
  [SCSI] zfcp: Remove ZFCP_DID_MASK
  [SCSI] zfcp: Move WKA port to zfcp FC code
  [SCSI] zfcp: Use common code definitions for FC CT structs
  [SCSI] zfcp: Use common code definitions for FC ELS structs
  [SCSI] zfcp: Update FCP protocol related code
  [SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport
  [SCSI] zfcp: Assign scheduled work to driver queue
  [SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
  [SCSI] zfcp: Implement module unloading
  [SCSI] zfcp: Merge trace code for fsf requests in one function
  [SCSI] zfcp: Access ports and units with container_of in sysfs code
  [SCSI] zfcp: Remove suspend callback
  [SCSI] zfcp: Remove global config_mutex
  [SCSI] zfcp: Replace local reference counting with common kref
  ...
2009-12-09 19:42:25 -08:00
Vasu Dev
4a84067dbf [SCSI] add queue_depth ramp up code
Current FC HBA queue_depth ramp up code depends on last queue
full time. The sdev already  has last_queue_full_time field to
track last queue full time but stored value is truncated by
last four bits.

So this patch updates last_queue_full_time without truncating
last 4 bits to store full value and then updates its only
current usages in scsi_track_queue_full to ignore last four bits
to keep current usages same while also use this field
in added ramp up code.

Adds scsi_handle_queue_ramp_up to ramp up queue_depth on
successful completion of IO. The scsi_handle_queue_ramp_up will
do ramp up on all luns of a target, just same as ramp down done
on all luns on a target.

The ramp up is skipped in case the change_queue_depth is not
supported by LLD or already reached to added max_queue_depth.

Updates added max_queue_depth on every new update to default
queue_depth value.

The ramp up is also skipped if lapsed time since either last
queue ramp up or down is less than LLD specified
queue_ramp_up_period.

Adds queue_ramp_up_period to sysfs but only if change_queue_depth
is supported since ramp up and queue_ramp_up_period is needed only
in case change_queue_depth is supported first.

Initializes queue_ramp_up_period to 120HZ jiffies as initial
default value, it is same as used in existing lpfc and qla2xxx.

-v2
 Combined all ramp code into this single patch.

-v3
 Moves max_queue_depth initialization after slave_configure is
called from after slave_alloc calling done. Also adjusted
max_queue_depth check to skip ramp up if current queue_depth
is >= max_queue_depth.

-v4
 Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f
to store or show its value.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04 12:00:44 -06:00